314 NORTH AMERICAN INSECTS. 
tics, differing here and there mainly in size, it is very diffi- 
cult to divide them into many different and distinct species. 
Nor do we propose to attempt it here; but so common an 
insect we could not omit, even in our brief history of North 
American diptera. We trust, however, to see a work on 
this subject ere long from Baron Osten Sacken, in which 
all the flies of our country will be properly and scientific- 
ally classed. 
There are few insects of which man and beast complain 
so much as of the mosquitoes. It is true that there are 
insects, such as wasps, bees, and the fleas we have just 
mentioned, that inflict painful and even dangerous wounds, 
but no other insect pursues us with such obstinacy, day 
and night, and is such a universal torment to man, as the 
mosquito. In some localities, particularly near rivers, lakes, 
and ponds, the inhabitants can scarcely invent means to 
protect them from the attacks of these insects; nor are our 
cities exempt from them, but almost every where they are 
found biting and sucking our blood during the day, and at 
night whistling and singing in our ears, preventing all sleep 
to those that are not covered with gauze. 
When traveling some years ago in the country of the 
Czernomorzi, or Cossacks of the Black Sea, we observed 
before each house of the different slanitzas, or villages, 
of the Cossacks, large heaps of half-dried manure ignited 
and smoking, which our driver informed us was for the 
purpose of keeping off the mosquitoes. ‘Toward evening, 
on a very hot June day, we ascended the right bank of the 
muddy and slowly-running River Kuban, on the left bank 
of which the independent Circassia stretched out before us, 
when suddenly swarms of small mosquitoes covered us, our 
servant, and driver, and horses, lighting upon us in lumps 
an inch thick, and, in spite of all the covering we could 
hastily throw over us, tormenting us excessively with their 
bites. 
